Prototyp-basierter Dependency-Injection-Container für React-Unit-Tests

function createTestContainer(parent = null) {
  const registry = Object.create(parent ? parent.registry : null);
  const cleanups = new WeakMap();
  return {
    registry,
    register(key, service, cleanupFn) {
      registry[key] = service;
      if (cleanupFn) cleanups.set(service, cleanupFn);
    },
    resolve(key) {
      const service = registry[key];
      if (!service) throw new Error(`Unresolved dependency: ${String(key)}`);
      return service;
    },
    teardown(service) {
      const cleanup = cleanups.get(service);
      if (cleanup) cleanup();
    }
  };
}